1. Field of the Invention
The present invention relates to a returning device of a wrench tool in which an auxiliary retainer is fixed without rotation by using an eccentric positioning of the auxiliary retainer and a positioning shaft so that the auxiliary retainer retain a bolt tool securely.
2. Description of the Prior Art
With reference to FIG. 1, a conventional open end wrench 1 disclosed in TW Pub. No. 1355990 comprises a handle H, the handle H includes an open driving portion 100 having a first jaw 110 with a first engaging face wall 114, a second jaw 120 with a second engaging wall 124, and a chamber 160 between the first jaw 110 and the second jaw 120. The first engaging wall 114 of the first jaw 110 includes a recessed section 112 formed thereon to receive a projection of a workpiece W during idly rotating process of the open end wrench, the second engaging wall 124 of the second jaw 120 includes an inner face 126 extending inward therefrom, and between an extending line of the second engaging wall 124 and the inner face 126 is defined a room 128, the inner face 126 includes an orifice 130 connecting with the room 128 to receive an auxiliary retainer 140 and a spring S, the auxiliary retainer 140 includes an abutting face 143 and a pressing face 144, both of which are fixed on one end of the auxiliary retainer 140, the auxiliary retainer 140 also includes a slot 148 arranged on an external side thereof, and the second jaw 120 includes a limiting element 150 inserted therein and engaged with the slot 148 so as to limit the auxiliary retainer 140 to move between a first unpressed position and a second unpressed position. Referring further to FIG. 2, as operating the open end wrench 1 to rotate the workpiece W, the auxiliary retainer 140 is located at the first unpressed position so that the abutting face 143 retains the workpiece W with the first jaw 110 and rotates the workpiece W. As shown in FIG. 3, in an idle rotating operation, the open end wrench is rotated reversely, and the pressing face 144 of the auxiliary retainer 140 is reacted by a peripheral side WS of the workpiece W so that the auxiliary retainer 140 moves back to a second position of the orifice 130, and then the open end wrench 1 can be rotated idly in an reverse direction. However, as manufacturing the orifice 130 and the auxiliary retainer 140 of the second jaw 120, to work the orifice 130 easily, the second jaw 120 is drilled to form a cylindrical orifice 130, and a column-shaped auxiliary retainer 140 matches with the cylindrical orifice 130 and rotates in the cylindrical orifice 130 randomly, but the abutting face 143 of the auxiliary retainer 140 can not contact the peripheral side WS of the workpiece W completely, so the slot 148 has to be arranged on the external side of the auxiliary retainer, and the limiting element 150 is inserted into the second jaw 120 to further engage with the slot 140 so as to limit the auxiliary retainer 140 to move linearly and to prevent the auxiliary retainer 140 from rotation, thereby positioning the abutting face 143 of the auxiliary retainer 140. To move the auxiliary retainer 140 smoothly, the slot 148 has to keep a suitable distance apart from the limiting element 150, but such a suitable distance will cause the auxiliary retainer 140 rotate slightly in the orifice 130, hence the abutting face 143 of the auxiliary retainer 140 can not retain the peripheral side WS of the workpiece W precisely and can not be positioned securely.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.